Brake mechanism



April 16, 1940.

E. o. SHREFFLER Er AL 2,197,321

BRAKE MECHANISM.

Filed May 1o, 1937 Y 2 sheets-sheet 1 y0 70 Aaron les@ e.

` INVENTORS 56 I a@ av Wwz'zw y?.

T HEIR ATTORNEYS April i6 1940- E. o. sl-IREFFLER Er AL 2,197,321

BRAKE MECHANISM Filed .May l0, 1957 2 Sheets-Sheet 2 l) fawn@ @S/#eww i Aaron legge.

INVENTOR S THE IR ATTORNEYS Patented Apr. 16, 1940 UNITED STATES eATENT oFF1cE.

's iolaims. (ci. 18s- 452) Our inventionirelates to brakes and includes among its objects and advantages the provisionof an improved power. brake unit co.operating in a novel` manner with the manually operated brake pedal for brakeapplying purposes.`

In the accompanyingdrawings: j I Fig. 1 is a sectional view of our invention illustrating the power unit attached to` the steering post for co-operationfwith the brakepedah.

'm Fig. .2 is a sectional view along the line 2 '-.2

of Fig. 1; f I I i v Fig. 3 is a sectional view along the line 3,-3 of Fig. 1; f

Fig. 4 is a sectional view. along theI lineg4-4- l of Fig. 1; Fig. 5 is a sectional View alongthe' line 5-5 ofFgB;Y

Fig. 6 isa sectional-view of a; diferent form of construction;l f' i 2.0 Fig. '1 is a .view taken from the positionindicated by line 1-1 of Fig. 6;

Fig. 8 is a sectional view of thev pendulum Valve; and i Fig. 9 is a sectional view .along the line '9-9 of Fig. 8. i

In the embodiment selected to illustrate our invention we makel use of a conventional brake pedal III pivotally mounted at I2- andfconnected with the brake mechanism, not shown,through v the medium of 'a conventional brake rod' I4.

Upon the steering post I6 we mount a power unit I8 which is operatively connected with the intake manifold (not shown) of the'engine of the vehicle through the medium of a conduit 20.

x A linkage 22 operatively connects the powerunit I8 with the brake pedal I0. I

Specically, the power unit I8 comprises drum sections 24 having anges 26 between which the marginal area of a flexible diaphragm 28 is pinched. Screws or bolts `3ll hold the sections I,

24 in assembled relation. To the outer. face of one of the sections 24 we weld a supporting plate 32 terminating in a right-angular. bend 34 having a curvature 36 for partlyembracing the steering post I6. A

curvature 36, and the twojparts are firmly clamped upon the steering post through' the medium o f boltsllll.v Thus, the power unit I8'is positioned to one side ofthe steering post I6 and may be shifted longitudinally of `the` steeringpost to secure precise location of the 'unit` On opposite .sides o f the diaphragm 28 we position metallic plates 42which plates arefproo vided with @pag-opeeiaa ifeli'geiirt a.

provide a groove 60 with-an air bleed 62 in the sleeve 50 in the normal position of the parts, as illustrated in Figs. 30

clamp member 38 pa rtly embraces the steering post --II` opposite kthe ments 16 formed integrallywith a plate'18 carcentral openingAB in the diaphragm 2 8 v(see Fig. 3).y The threaded end 48 on a sleeve 50 passes through vthe aligned openings 44 and. 46, and the three parts are firmly connected into a. untary assembly by means of nuts52 which bear 5 against theouter faces ofthe plates l42. Fig.

1 .illustrates the normal position of the diaphragm 28. 1'

' .One of the drumfsections 24 is provided with an opening 541through which thesleeve 58 eX- y1I) tends. lThe opening 54 vis larger than the outer diameter of the sleeve 50 to permit free relative movement` of the sleeve. Within the sleeve- 5 0 we slidably mount a Vvalve element156; in the nature of a tube which may .haver communica- 1 tion with the powergunt I8 to the .left ofthe diaphragm 28. when viewing Fig. l through the mediumpf an opening 51. The opening 51 is normally covered by the sleeve 5I), but the valve element 56 may be shifted -inwardly ofthe sleeve 20 50 for positioning the opening 51 beyondA the .inner end ofithe. sleeve 5I).` =Valve element 56 includes a neck 58 to which the flexible `conduit 20 is connected for establishing communication.

of the vehicle.

In the outer wall of the valve element lv26 we whichy has communication 1 and 3. Becausev of such-.communication be' -tween the air bleed 62 and the groove 60, suction incident to the intake manifold is rendered inoperative with respectto thediaphragm 28 vuntil the airbleed ismoved out of registration 35 with the groove andthe opening 51 shited be' yond the inner end of the sleeve 5D.

The linkage `22 comprises alever 64l having branchesz66 at its upper endslotted Iat 68 to receive -pins 1I) xedly connected with the v alve 40 element 56. In Fig. 3, we illustratethe pins 10 as-havi11g`threaded relation with vthe valve element 56 lfor ,connection purposes.

The lowervend otv` the lever 64 an offset plate. 12

14 arranged withits ends between` boredabut terminates in lried by a power lever 8D.' Y'Plate 12 is' pivotal ly connectedwitn the 'abutments `1s through thev vmedium of a'shaft`82' whichextends through the. 5I)

operation while thep'ower lever 80 constitutes' a mechanical connection I be 'ween the pow having a bored enlargement, 45 i l is shifted. The spring unit S0 comprises a single piece of spring wire bent to provide a U-shaped part 92 which embraces the lever 80. The wire is convoluted at S4 and mounted upon a pin v895 carried by the lever 80 while` the convolutions 94 terminate in reaches 98 looped for connection with pins |00 having threaded relation with the sleeve 50 (see Figs. 3 and7 4).

The spring unit 80 is so shaped as to maintain the plate 18 in slight pressure relation with the head I 02 of the ybrake pedal-in the normal position of the brake pedal. Since the normalpressure i relation between the lever 80 and thebrake pedal ||l is innitesimal, the tension of the spring unit 90 in the normal position of the parts will not cause any depressionof the brake pedal I0, which pedal may be yieldingly supported in the normal position of Fig. 1 by a spring |04 having one end connected with the pedal llland its opposite end xedly connected with any suitable anchorage on the vehicle. Such springs are well known inthe art and need not be described in further detail.

Between the plates 12 and 18 we mount a compression spring !06 which operates to maintain normal separation of the plates `12A and 18 in the manner illustrated in" Fig. 1. In Fig. 3, the pins |00 have their inner endsflying within the grooves |08 in the valve element 56, the grooves being so located and of such length as to prevent outward movement of the valve element with respect to the sleeve 50 beyond the positions illustrated in Figs. l and 3. y l

- In operation, pressure is applied to the `plate 12 for compressing the spring M36- Because of the location of the pivot 82, a very slight cornpression of the spring |86 shifts the upper end of the lever 64 sufficiently far lto bring the opening 62 out of registration with the groove 60 and the opening 51 to a position beyond the inner end vof the sleeve 50. As the lever 64 moves in the direc-tion of itsdotted line illustration I l0, the power lever 80 remains in the full line position of Fig. 1 until the-suction of the intake manifold has been made eiective on the diaphragm 28.

Movement ofv the diaphragm 28 in the direction of its dotted line position carries with it the sleeve 50. Such shifting of the sleeve tends to flex the spring unit 80 which, in turn, exerts a pull on the power lever 80 for moving it in the direction of its dotted line position of Fig. 1, thus operatively connecting the power unit 8 with the brake pedal I0 for brake applying purposes. Movement of the. sleeve 50 with the diaphragm 28 is relative to the valve element 56 so that the air bleed 62will again communicate with the groove 60, and the opening 51 will again be covered by the sleeve 50. The springunit 80 is suicientlystif to transmit the desired brake applying forcesto the power lever 80, but asv these forcesexceed the critical value of the spring unit,

continued flexing of the` spring unit cuts 01T the communication'between the intake manifold' and kthe power unit.

`connected at -brake unit. lLever |40l includes a shaft |44 Further compression of the spring |06 vwill again pivot the lever 64 about its axis 82 for establishing communication between the intake manifold and the power unit. Thus, the brake applying forces of the power unit i8 may be continued in stages within the total range of adjustment of the brake pedal l0. Release of manual pressure on the plate 12 with the brakes applied in any degree will bring about registration between the groove 60 and the bleed 62 and closure of the opening 51 for rendering the power unit I8 inoperative. In Figs. 6 to 9, inclusive, we illustrate a diierent form of construction which may be located within the vehicle in the same manner as the previously described system, but in which a pendulum valve is interposed in the system for setting the power unit in operation in response to negative acceleration of the speed of the vehicle. In Fig. 6, the power unit 2|0 includes a clamp |22 for connection with the steering post |24 in the same way as the power unit |8. The powerunit |20 comprises sections |26 and |28 flanged Aat |30 for connection purposes as well as for mounting the diaphragm |32. Section |26 includes a relatively large opening |34 for accommodating a rod |36 having one end fixedly connected with the diaphragm |32 and its oppositeend pivotally |42 with thev section |26 of the slidably mounted in a tube |46 pivotally connected at |48 with the head. |50 vof the brake pedal |52. The brake pedal is conventional and is operatively connected with `the `usual rod |54 associated with the brakes, not shown. Brake pedal |52 is pivotally mounted at it` in the same way as the brake pedal l0 and includes a spring |58 corresponding to the spring |04.

Section |28 of the power unit |20 communicates with a cylinderl |68, 4through the medium of a conduit |62. `One end of the cylinder |66 is clamped in a band` |64 having a right-angular bend |66 attached to the vehicle wall |68 by bolts 1i).` A conduit |12.,establishes communication between the cylinder |60 and the intake,

manifold, not shown. Y

In Fig. 8, we illustrate. the cylinder |60 :as being provided with a piston |14 yhaving a slot |16 normally aligned with a slot |18 inthe wall of the cylinder. tion of the piston, at which time the port |88 communicating with the conduit |12 is closed. A partition |82'is provided in the piston, which is otherwise tubular,- and one end of the piston is closed by aI plate |84. The piston may be'gcounterbored at |86 (see Fig. .9) `for the reception of the plate |84, which plate islmade secure by bendingthe material of the piston over the plate, as at |88.

. Two slots |90 are provided in the piston |14 to accommodate a shaft .|92 passing'through openings |94 in the cylinder |601and rived as at |96. Because ofthe slots |90, the piston is free to move within predetermined limits relative to vthe fixedshait-ISL Upon -the shaft |82 we rotatably mount an actuating element A=| 98-"havin g cam velements 200 and 202arrangedinrcontact'with the innerfface of the 'plate 184. The actuating `element' |88-is formed integrally 'with an arm 204 which, in' turn, carriesa 'weight'206.- We slot the piston |14 at 208 andthe cylinder 60 at'2|0'to accommodate -tliearm204. "Afslot 2|2 is provided injthe y`upperjpart rof the piston |14 for accommodating the cam member 202;l A spring 2141s mounted/inside 'the' cylinder 'l 68V Fig. .8 ilustrates the normal posiamasar site end abutting a plug 2|6 having threaded relation with the cylinder. The spring exerts a slight pressure on the plate |84 soas to prevent accidental shifting of the piston |14 to the Lright when viewing Fig. 8. Since the plate |84 engages both cams 200 and 202 in the position of Fig, 8, shifting of the piston in the opposite drection is prevented since between the two cams and the plate isbalanced.

In operation, the brake pedal |52 may be depressed in the usual manner. With the brakes applied to a suflicientdegree to cause negative acceleration of the caused to swing in the direction of travel, which causes the cam 202 to advance the piston |14 to the right when viewing Fig. 8 for uncovering the port |80. After port is uncoveredcommunication is established between the power unit |20 and the intake manifold, at which time the power unit is set in operation forv brake applying purposes.

Any pull on the, shaft |36 connected with` the diaphragm |32 causes a pivotal action ofthe lever |40 which, in turn, applying pressure to the brake pedal |52. The telescopic relation between the shaft |44 andthe tube |46 provides accommodation for variable spacing between the axes |42 and |48 incidentto adjustment of the brake pedal. Slight shifting of the piston |14 from the normal position of Fig. 8 brings the slots |16 and |18 outjof registration so that the suction of theintake manifold is effective on the diaphragm |32. Communication between the intake manifold and thepower unit |20 is maintained untilthe suction within the cylinder |50 is of a suiicient degree to movethe piston |14 toward its normal position against'y the -action of the weight 206. As the suction between the intake manifold and the power unit iscut off,

communication can again be established upon furtherY depression ofthe brake pedal |52 for again retarding the speed of the vehicle and setting the weight 206 in operation for establishing communication between the intake manifold and the power unit. The power unit |20 may be set in operation in stages within the adjusting range of the brake pedal |52.

Since two cams are employed, the cam 200 will be actuated for shifting the piston |14 in the` same manner as the cam 202 in response to negative acceleration of the vehiclewhen moving in reverse. Thus, the power unit |20 is effective in both directions of travel of thevehicle.

In both forms of the invention the power unit is operatively connected with a brake pedal and brake mechanism of conventional design. The construction and arrangement are such as to permit the installation of the power unit without necessitating redesign of the brake pedal or the brake mechanism. Both forms are easily installed and are so located as. to be easily accessible for adjustment and repair. According to Figs. 6 and '7, the head |50 may be provided with a lug 2|8 for pivotal connection with the tube |46. This lug may be welded or otherwisesecured to the head |50.

Without further elaboration, the foregoing will so fully explain our invention that othersv may, by applying current knowledge,` readily adapt the same for use under various conditions of service.

We claim:

l. The combination with a steering'post and a brake pedal, of a power unit mounted on the steering post including a diaphragm, a hollow the pressure relation vehicle, the weight 206 is' member xedly connected with ythe diaphragm and having an opening, a tube slidable in said ,hollow member and having a groove normally communicating with said opening and the interior of the' power unit, a suction line communicating with said tube, a power lever pivotally conf nectedwith the power unit intermediate its ends vand having one end connected with said hollowv nmemberand its opposite end operatively related to: said brake pedal, and a lever pivotally connected with thepower lever and having one end connected withsaid tube for vshifting the same, to movel the groove therein out of registration with said opening for establishing communication between the suction line and the power unit, said last-named lever including a pressure ele- `ment. f

2 In a motor vehicle including an operators compartment and a brake pedal, a power'unit including a diaphragm located in said compartment,fa` suction line including valve means supported by the diaphragm and interposed inthe suction line, an operating connection between the valve means and the brake pedal, and manually actuated control means for the power unit, said operating connection being arranged. to press downwardly on the brake pedal when the manually actuated control means are actuated for an operating linkage betweenl the valve means and, lsaid brake pedal for establishing communication between the suction line and .the power unit when pressure is applied to the brake pedal, s aidfoperating linkage including a powerlever and a valve means actuating lever pivotally connected with the power lever, said valve means .actuating lever having an end overlying `the brake pedal constituting a foot pressure element.

4, In a motor vehicle including a steering po-st and a brake pedal, a power unit including a diaphragm mounted on said steering post, a suction line including valve means carried by the diaphragm and interposed in the suction line, an operating linkage between the valve means and said brake pedal for establishing communication between the suction line and the power unit when pressure is applied to the brake, a power lever operatively associated with the brake pedal, and a resilient `connection between the power lever and the diaphragm. i

5. In a motor vehicle including an operators compartment and a brake pedal, a power unit mounted on a fixed support inside the compartment including a diaphragm, a hollow member 60 xedly connected with the diaphragm and having an opening, a tube slidable in said hollow member and having a groovenormally communicating with said opening and the interior of g tion between the suction line and the power unit,

said last-named lever' including a pressure element. v

6. In a motor vehicle including a brake pedal, a power unit including a diaphragm 'mountedon a Xed support,` a suction line including lvalve means carried by the diaphragm and interposed in the suction line, an operating linkage between the Valve means and said brakeA pedal vfor `es` tablishing communication between the 'suction line and the power unit when pressure is applied to the brake, a power lever operativelyassociated with the brake pedal, and a resilient' connection between the power lever and the diaphragm.

7. In combination with an automotive vehicle -brake lever, a power unit including a suction responsive element, a suction line connected with the power unit for actuating said suction responsive element, a valve comprising a housing operatively connected with said suction responsive element and a valve element movable in the housing for opening and closing the suction line, a yieldable foot actuated means operatively connected with said valve element for opening said suction line through shifting of the valve element relatively to saidhousing, and an operating connection between said housing and said brake lever for moving the latter to brake applying position, including yielding means coacting with said housing to yield on the application of a predetermined braking force on the brake lever to permit the housing to shift relatively to said valvev element for closing the suction line.y

8. In combination with an automotive vehicle brake lever, apower unit including av suction responsive element, a suction line communicating with the power unit for actuating said suction responsive element, a valve comprising a housing operatively connected with ysaid suction responsive element and a valve element movable-in the housing for opening and closing said suction line, a foot actuated means operatively connected with said valve element for opening said suction line through shifting of the valve elementl relatively to Asaid housingincluding. va resilient ele'- ment opposed by the brake lever and yieldingly resisting movement of the foot actuated means, andan operating connection between said housingi and said brake lever for moving the latter to a brake applying `position,.including a spring interposed in said operating connection and co- -acting with said housing to yield on the applicaltion of a predetermined braking force to the brake lever to permit said housing to shift relatively to said valve element for closing the suction'line.

9. In combination with an automotive vehicle brake lever, a relatively xed drum having a suction responsive diaphragm, a suction line connected with said drum for actuating said diaphragm, a valvecomprising a housing operatively connected with said diaphragm and a valve element movable in said housing for opening and closing said suction line, said valve normally maintaining communication between said drum and the atmosphere to permit said diaphragm to assume its normal position inside the drum, afoot actuated means operatively connected with said valve element for opening said suction line through shifting of the valve element relatively to'said housing to create suction condition inside the drum for actuating the diaphragm, a spring opposed by said brake lever and operatively connected with said foot actuated means to yieldy upon thel application of a predetermined force for shifting the valve element, and an operating connection between said housing and said brake lever for moving the latter to brakeapplying position when the diaphragm is actuated,

including a spring interposed in said operating connection and coacting with said housing to yield upon l*the application of a predetermined braking force onthe brake lever to permit the housing-to shift relatively to said valve element for closing the suction line.

ELWYNE Oi. SHREFFIER.

AARON D. LESAGE. 

